The tuned circuits of capacity and inductance used in vacuum tube transmitter circuits are frequently called `tank` circuits, because from one viewpoint they act as tanks or reservoirs of RF energy. Blocking Capacitors. -Blocking capacitors are used to provide a high impedance path for DC or low-frequency AC, and so prevent the flow of such currents
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without appreciably affecting the flow of RF. Series and Parallel Feed. -The DC grid and plate voltages required for tube operation may be fed through the coil of the tuned circuit, or may be fed through a choke in parallel with the tuned circuit. In the first case the voltage feed is called series feed, in the second, it is called parallel feed. The connections are shown in Figure 59. Filament Center-Tap. -When filament type tubes are heated by AC, the grid and plate returns must be made to the electrical center, or center-tap, of the filament circuit in order to avoid hum. Excitation. -In transmitters, the AC signal voltage applied to the grid of a tube is called the excitation, or the exciting or driving voltage. Exciting or driving power is the power required to develop the exciting voltage across the grid circuit. Oscillators supply their own excitation, but amplifiers must be driven by voltage from an oscillator or from another amplifier. Power Input. -Unless otherwise specified, the term power input applies to the DC power consumed in the plate circuit. It is the product of the DC plate voltage and current. Power Output. -It is important to distinguish between the tube power output and the circuit power output. The tube output does not take into account the tank and coupling circuit losses. Antenna Feeding. -Distances along an antenna are usually expressed in terms of electrical wave length. Every half wave length...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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